Typically in cameras, there are mechanical shutters used to control the exposure time of an acquired image. Shutter allows a certain amount of light to pass to the imaging sensor within a certain timeframe. By using a high-speed shutter, the image can be captured instantly in order to reduce or eliminate motion blur and a sharper image can be achieved. The shutter also allows more time to be used for transferring the image from the imaging sensor to an image processor by preventing new exposure. The shutter enables synchronization with the use of xenon flash, for example. Generally shutters are mechanical components containing one or more blades to implement the closing function.
Minituarization has currently become a problem with the conventional shutter structures. It is generally difficult to achieve an ultra fast shutter (e.g 1/4000 second) only with shutter blades in a conventional shutter design. When using bright xenon flash with the camera, an additional moving neutral density filter is typically used in a conventional shutter unit. This additonal moving part adds to the complexity of shutter design.
It would be advantageous and desirable to achieve a fast shutter unit that can be used in a miniature camera or in a mobile phone camera.